io_uring: add lockdep assertion in io_fill_cqe_aux

Add an assertion for the completion lock to io_fill_cqe_aux

Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-8-dylany@meta.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>